YouTube-style keyboard controls on Showtime

Use similar controls as on YouTube when watching Showtime (`f` for full screen, `k` to play/pause, `c` for captions)
当前为 2021-01-18 提交的版本，查看最新版本。
换行
// ==UserScript==
// @name         YouTube-style keyboard controls on Showtime
// @namespace    showtime.keyboard
// @version      0.1
// @description  Use similar controls as on YouTube when watching Showtime (`f` for full screen, `k` to play/pause, `c` for captions)
// @match        https://showtime.com/*
// @match        https://www.showtime.com/*
// @grant        none
// ==/UserScript==

(function() {
    'use strict';

    // change these constants if you prefer to use a different key
    // (or change the letter to uppercase if you want the shortcut to require the use of Shift)
    const FULL_SCREEN_KEY = 'f';
    const PLAY_PAUSE_KEY = 'k';
    const CLOSED_CAPTIONS_KEY = 'c';

    function clickButton(className) {
        const buttons = document.querySelectorAll('button.' + className);
        if (buttons && buttons.length == 1) {
            buttons[0].click();
        } else {
            console.error('Button not found!');
        }
    }

    function isPlaying(videoElement) {
        return !!(videoElement.currentTime > 0 && !videoElement.paused && !videoElement.ended && videoElement.readyState > 2);
    }

    addEventListener("keypress", function(e) {
        if (e.ctrlKey || e.altKey) { // return early if any modifier key like Control or Alt is part of the key press
            return;
        }

        if (e.key == FULL_SCREEN_KEY) {
            if (window.innerHeight == screen.height) {
                clickButton('exit-fullscreen');
            } else {
                clickButton('enter-fullscreen');
            }
        } else if (e.key == PLAY_PAUSE_KEY) {
            const videos = document.getElementsByTagName('video');
            if (videos && videos.length == 1 && isPlaying(videos[0])) {
                clickButton('pause');
            } else {
                clickButton('play');
            }
        } else if (e.key == CLOSED_CAPTIONS_KEY) {
            const ccContainer = document.querySelectorAll('div.player-closed-captioning-container > div');
            if (ccContainer && ccContainer.length == 1) {
                if (ccContainer[0].classList.contains('closed-captioning-enabled')) { // already enabled
                    clickButton('closed-captioning-disable');
                } else {
                    clickButton('closed-captioning-enable');
                }
            } else {
                console.error('No CC container found');
            }
        }
    });
})();